"Cyberspace has come to be widely understood as a practical deconstruction of essentialism. Out there, bodies, and identities alike may lose their connection to terrestrial limits, extending through a new range of possibilities, and in the process may reflect back upon the supposed naturalness, givenness, reification or territorialization of real life bodies and identities." Don Slater
When we approach a virtual space (ie walk up to a computer, don a pair of VR goggles) what happens to our relationship to our body? Do we go to a different space? Do we become a different person? Perhaps we only become altered versions of ourselves, enhanced in the new environment as technology allows. Many theorists are proposing that we lose touch with our identity and reconfigure ourselves again "on the other side."
I propose that using a cyberspace technology is no different than feeling the emotions of the protagonist in an engaging novel. Reading a book is a tremendous way to activate many parts of our neurology and we often feel the same as the character in a good book. Although we can become "immersed" in a good book nobody would argue that we are entering the book's diegetic reality when we pick it up.
The difference for me lies in how involved the user becomes. Books clearly loose out to virtual reality by this definition. Cyberspace can become a territory that you exist above and beyond your terrestrial body.